Mael Sechnaill mac Domnaill

Mael Sechnaill mac Domnaill (948-2 September 1022) was King of Mide from 976 to 2 September 1022 (succeeding Muirchertach mac Mael Sechnaill and preceding Mael Sechnaill Got mac Mael Sechnaill) and High King of Ireland from 980 to 1002 (succeeding Muirchertach mac Mael Sechnaill and preceding Brian Boru) and from 1014 to 1022 (succeeding Brian Boru and preceding Diarmait mac Mail na mBo).

Biography
Mael Sechnaill mac Domnaill was born in Ireland in 948 to the Colman branch of the O'Neill dynasty, and he was the great-great-grandson of Mael Sechnaill mac Maele Ruanaid. He succeeded to the kingdom of Mide in 976 and as High King of Ireland in 980, and he defeated the Viking king Amlaib Cuaran near the Hill of Tara. In 997, he agreed to divide Ireland with the increasingly powerful King of Munster Brian Boru, and he handed over the title of High King in 1002. However, the death of Brian, his son, and his grandson at the Battle of Clontarf in 1014 enabled Mael Sechnaill to rise to the High Kingship once again, and he reigned until his death in 1022.